Miniature pressure/force sensor with integrated leads

ABSTRACT

A pressure/force sensor comprises a diaphragm structure including a sensing element and a lead structure extending from the diaphragm structure and including first and second traces electrically coupled to the sensing element. The diaphragm structure and the lead structure include a circuit assembly comprising a common insulating layer and a common conductor layer on the insulating layer. The conductor layer includes at least a portion of the sensing element and at least the first trace. In embodiments the sensing element includes electrodes. In other embodiments the sensing element includes a strain gauge.

REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the following U.S. Provisionalapplications, both of which are incorporated herein by reference intheir entireties and for all purposes: Ser. No. 62/290,789 filed on Feb.3, 2016 and entitled Miniature Pressure/Force Sensor with IntegratedLeads; and Ser. No. 62/403,765 filed on Oct. 4, 2016 and entitledMiniature Pressure/Force Sensor with Integrated Leads-AdditionalEmbodiments.

FIELD OF THE INVENTION

The invention relates generally to pressure/force sensors havingintegrated leads, and subtractive, additive and/or semi-additiveprocesses for manufacturing the sensors.

BACKGROUND

Pressure and force sensors (e.g., capacitive-type and strain gauge-type)are known and used in a wide range of applications. There remains,however, a continuing need for improved pressure and force sensors.Advantageous features of such improved sensors can include the abilityto use manufacturing processes that enable the efficient and high volumemanufacture of the sensors, robust design space capabilities enablingsensors operable over a wide range of pressures and forces, thermal andmoisture stability, small size and suitability to a range ofapplications.

SUMMARY

One embodiment of the invention is a capacitive-type pressure/forcesensor including: a diaphragm structure including first and secondelectrodes; a lead structure integrally formed with at least a portionof the diaphragm structure and extending from the diaphragm structure,the lead structure including first and second traces electricallycoupled to the first and second electrodes, respectively; and wherein atleast portions of both the diaphragm structure and the lead structureinclude: a layer (optionally a common layer) of insulating polymer; aconductor layer (optionally a common layer) on layer of insulatingpolymer, including the first and second traces. In embodiments, thediaphragm structure includes: a void region; and a portion of theinsulating polymer extending over the void region, and wherein one ofthe electrodes is on the portion of the insulating polymer extendingover the void region. In embodiments, the electrode on the insulatingpolymer includes a sputtered conductor layer. In embodiments, the firstand second traces include the sputtered conductor layer; and theconductor layer including the first and second traces includes a platedlayer on the sputtered conductor layer. In embodiments, the diaphragmstructure and optionally at least portions of the lead structure furtherincludes a base, and wherein the base defines the void region and theportion of the insulating polymer extending over the void region extendsover at least portions of the base. In embodiments, the base includes(and optionally consists of) metal such as stainless steel. Inembodiments, the base includes a partial etched pocket defining the voidregion. In embodiments, the sputtered conductor layer and the traces areon a side of the insulating polymer layer opposite the base. Embodimentsfurther include at least one conductive via, the via electricallyconnecting one of the traces to one of the electrodes through theinsulating polymer. In embodiments, one of the electrodes includes themetal base, and the via electrically connects one of the traces to themetal base. Embodiments further include a layer of adhesive securing theinsulating polymer to the base.

Another embodiment of the invention is a capacitive type pressure/forcesensor, including: a diaphragm structure, including: a base memberdefining a void region; a first diaphragm portion insulating polymerlayer on the base member, and optionally on a first side of the basemember, and extending across a first side of the void region; a firstsputtered conductor layer including an electrode on the first diaphragmportion insulting polymer layer and over the void region; a seconddiaphragm portion insulating polymer layer on the base member, andoptionally on a second side of the base member, extending across asecond side of the void region; and a second sputtered conductor layerincluding an electrode on the second diaphragm portion insulatingpolymer layer and over the void region; and a lead structure integrallyformed with the diaphragm structure and extending from the diaphragmstructure, the lead structure including: a lead portion insulatingpolymer layer (that is optionally common with the first diaphragmportion insulating polymer layer); and first and second traces on thelead portion insulating polymer layer, wherein the first and secondtraces are electrically coupled to the first and second electrodes,respectively. In embodiments, the first sputtered conductor layer andthe first trace are on a first side of the lead portion and firstdiaphragm portion insulating polymer layer, opposite the commoninsulating polymer layer from the first void region and the base member.In embodiments, the first and second traces include the first sputteredconductor layer. In embodiments, the base member includes (andoptionally consists of) conductive metal such as stainless steel; thesecond sputtered conductor layer is on a first side of the seconddiaphragm portion insulating polymer layer and extends over a portion ofthe conductive metal base member; and the sensor further includes aconductive via electrically connecting the second trace to theconductive metal base member through the insulating polymer layer. Inembodiments, the metal base member includes: first and second sections;and a securing structure, optionally one or more welds or adhesive, tomechanically (and optionally electrically) join the first and secondsections.

Another embodiment of the invention is a capacitive type pressure/forcesensor, including: a diaphragm structure including: a base section (thatoptionally includes or optionally consists of metal such as stainlesssteel); a diaphragm insulating polymer layer on at least a portion ofthe base section; a first conductive electrode on the diaphragminsulating polymer layer; a conductive diaphragm electrode, optionallystainless steel; an adhesive insulating polymer layer joining theconductive diaphragm electrode to the base section; and a void regionbetween the first conductive electrode and the conductive diaphragmelectrode; and a lead structure integrally formed with the diaphragmstructure, including: a lead insulating polymer layer that is optionallycommon with the diaphragm insulating polymer layer; and first and secondtraces on the lead insulating polymer layer, wherein the first andsecond traces are electrically connected to the first conductiveelectrode and the conductive diaphragm electrode, respectively.Embodiments further include a conductive via electrically connecting thesecond trace to the conductive diaphragm electrode through the adhesiveinsulating polymer layer. Embodiments further include a polymercovercoat over the first and second traces and optionally any and allother portions of the sensor. Embodiments further include anencapsulating coating, optionally one or more of Ti/SiO₂, ornon-hygroscopic polymer, over at least the diaphragm structure.

Another embodiment of the invention is a strain gauge-typepressure/force sensor including: a diaphragm structure including one ormore strain gauges; a lead structure integrally formed with at least aportion of the diaphragm structure and extending from the diaphragmstructure, the lead structure including first and second and optionallymore traces electrically coupled to the one or more strain gauges; andwherein at least portions of both the diaphragm structure and the leadstructure include: a layer (optionally a common layer) of insulatingpolymer; a conductor layer (optionally a common layer) on layer ofinsulating polymer, including the first and second traces.

Other embodiments include additive, semi-additive and/or subtractivemethods for manufacturing the sensors.

Another embodiment comprises a method for manufacturing the sensors,including: commonly forming the insulating polymer layer of thediaphragm structure and the lead structure; forming the first and secondtraces on the common insulating polymer layer; and laminating the commonpolymer layer having the first and second traces thereon to a componentof the diaphragm structure or a layer of material from which thecomponent of the diaphragm structure is formed (i.e., forming the tracesbefore laminating the polymer layer to the diaphragm structure). Inembodiments, forming the first and second traces includes: sputtering aseed layer on the insulating polymer layer; and plating conductive metalon the seed layer. Embodiments further include: forming the electrode orstrain gauge on the common insulating polymer layer; and laminating thecommon polymer layer having the first and second traces and theelectrode or strain gauge thereon to a component of the diaphragmstructure or a layer of material from which the component of thediaphragm structure is formed (i.e., forming the traces and electrode orstrain gauge before laminating the polymer layer to the diaphragmstructure).

Another embodiment comprises a method for manufacturing the sensors,including: forming a component of the diaphragm structure or providing alayer of material from which the component of the diaphragm structure isformed; laminating common polymer layer without the first and secondtraces to the component of the diaphragm structure or a layer ofmaterial from which the component of the diaphragm structure is formed;forming the first and second traces on the common polymer layer afterthe laminating step. In embodiments, forming the first and second tracesincludes: sputtering a seed layer on the insulating polymer layer; andplating conductive metal on the seed layer. Embodiments further include:forming an electrode on the common insulating polymer layer; andlaminating the common polymer layer having the first and second tracesand the electrode thereon to a component of the diaphragm structure or alayer of material from which the component of the diaphragm structure isformed after the laminating step.

Another embodiment comprises a capacitive-type pressure/force sensorincluding a diaphragm structure comprising: a base portion; a movingportion; spring arms connecting the moving portion to the base portion;an electrode on the moving portion; and a trace extending from theelectrode. In embodiments, the base portion, moving portion and springarms are formed from a spring metal layer; the sensor includes aninsulating layer on the spring metal layer; and the trace is on theinsulating layer. In embodiments, the trace and insulating layer extendalong at least one spring arm.

Another embodiment is a capacitive-type pressure/force sensor includingone or more trace members comprising a diaphragm portion and a leadportion, wherein each trace member includes: a base layer that isoptionally spring metal such as stainless steel; an insulating layer onthe base layer; a conductor layer on the insulating layer opposite thebase layer; an electrode in the conductor layer of the diaphragmportion; and a trace in the conductor layer extending from the electrodeover the lead portion. Embodiments comprise a sensor including a twotrace members of the type recited immediately above, wherein the baseelectrodes of the trace members face one another in the diaphragmportion. In embodiments, the base layers are connected (e.g., at theirperipheries). Embodiments further include a spacer between the baselayers. Embodiments include two trace members of the type recited above,wherein the base layers are connected (e.g., at their peripheries) todefine a cavity, and the electrode on one of the trace members isopposite the insulating layer from the cavity (i.e., one electrode isoutside of the cavity. Embodiments include a trace member of the typerecited above and a can over the electrode at the diaphragm portion todefine a cavity. In embodiments, the can is metal, functions as anelectrode, and is electrically connected to a metal base of the tracemember. In embodiments, the trace member includes a trace that iselectrically connected to the can. In embodiments, the diaphragmstructure includes: a base portion; a moving portion; and spring armsconnecting the moving portion to the base portion. In embodiments, thebase portion, moving portion and spring arms are formed from a springmetal layer. Embodiments further include a layer of relatively highdielectric constant and/or elastomeric material on the electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, B, C, D, E and F are top, bottom, side, distal end, proximalend and detailed sectional isometric views of a sensor in accordancewith embodiments of the invention.

FIGS. 2A-2N illustrate sequences of process steps that can be used tomanufacture embodiments of the sensor.

FIGS. 3A-3I illustrate sequences of process steps that can be used tomanufacture embodiments of the sensor.

FIGS. 4A, B, C, D, E and F are top, bottom, side, distal end, proximalend and detailed sectional isometric views of another sensor inaccordance with embodiments of the invention.

FIGS. 5A-5S illustrate sequences of process steps that can be used tomanufacture embodiments of the sensor.

FIGS. 6A-6K illustrate sequences of process steps that can be used tomanufacture embodiments of the sensor.

FIGS. 7A, B, C, D, E, F and G are top, bottom, side, distal end,proximal end, isometric and detailed sectional isometric views ofanother sensor in accordance with embodiments of the invention.

FIGS. 8A-8P illustrate sequences of process steps that can be used tomanufacture embodiments of the sensor.

FIGS. 9A-9L illustrate sequences of process steps that can be used tomanufacture embodiments of the sensor.

FIGS. 10A, B, C, D, E and F are top, bottom, side, distal end, proximalend and isometric views of a cluster sensor in accordance with otherembodiments of the invention.

FIGS. 11A-11O illustrate sequences of process steps that can be used tomanufacture embodiments of the sensor.

FIGS. 12A-12I illustrate sequences of process steps that can be used tomanufacture embodiments of the sensor.

FIGS. 13A, B, C, D, E and F are top, bottom, side, distal end andproximal end views of a cluster sensor in accordance with otherembodiments of the invention.

FIGS. 14A-14Q illustrate sequences of process steps that can be used tomanufacture embodiments of the sensor.

FIGS. 15A-15J illustrate sequences of process steps that can be used tomanufacture embodiments of the sensor.

FIGS. 16A, B, C, D, E and F are top, bottom, side, distal end, proximalend and detailed sectional isometric views of another sensor inaccordance with embodiments of the invention.

FIGS. 17A-17MM illustrate sequences of process steps that can be used tomanufacture embodiments of the sensor.

FIGS. 18A-18N illustrate sequences of process steps that can be used tomanufacture embodiments of the sensor.

FIGS. 19A, B, C, D, E and F are top, bottom, side, distal end, proximalend and detailed sectional isometric views of a strain gauge-type sensorin accordance with embodiments of the invention.

FIGS. 20A-20U illustrate embodiments of a sequence of process steps thatcan be used to manufacture the sensor.

FIGS. 21A and 21B are isometric views of another sensor having flippedtwo trace assemblies with welded base members in accordance withembodiments of the invention, with FIG. 21A illustrating a first orupper side of the sensor, and FIG. 21B illustrating an opposite secondor lower side of the sensor.

FIGS. 22A and 22B are exploded views of the sensor in accordance withembodiments, with FIG. 22A illustrating the sensor components from theirupper or top sides, and FIG. 22B illustrating the sensor components fromtheir lower or bottom sides.

FIGS. 23A and 23B are sectional isometric views of the sensor inaccordance with embodiments of the invention, with the section linesextending through the diaphragm structure.

FIG. 24 is an isometric view of an integrated lead and can sensor havinga diaphragm structure and integrated lead structure in accordance withother embodiments of the invention.

FIG. 25 is detailed isometric view of the sensor, with portions of thecan broken away to expose portions of the trace member within thediaphragm structure.

FIG. 26 is a detailed sectional view of a portion of the diaphragmstructure of the sensor.

FIG. 27 is an isometric and partial cut-away illustration of anothersensor in accordance with embodiments of the invention

FIGS. 28-30 are isometric illustrations of another sensor in accordancewith embodiments of the invention.

FIG. 31 is sectional isometric view of another sensor having a diaphragmstructure and integrated lead structure in accordance with embodimentsof the invention.

FIG. 32 is an exploded view of the sensor.

FIG. 33 is an isometric view of a sensor having a diaphragm structureand integrated lead structure in accordance with other embodiments ofthe invention.

FIG. 34 is a view of the sensor with the trace member removed.

FIGS. 35, 36, 37A, 37B, 38A and 38B illustrate and describe a sensor inaccordance with yet additional embodiments of the invention.

FIGS. 39A and 39B are isometric illustrations of a sensor in accordancewith still other embodiments of the invention.

FIGS. 40 and 41 are exploded views of the sensor, taken generally fromthe side shown in FIG. 39A.

FIGS. 42 and 43 are exploded views of the sensor, taken generally fromthe side shown in FIG. 39B.

FIG. 44 is a partially exploded view of the sensor, with a covercoatlayer hidden.

FIG. 45A illustrates the conductor layer of the top circuit portion.

FIG. 45B illustrates the conductor layer of the fixed circuit portion.

FIGS. 46A, 46B and 46C are top isometric, cross sectional and bottomisometric views of a strain gauge sensor in accordance with otherembodiments of the invention.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Embodiments of the invention include capacitive-type and straingauge-type pressure/force sensors having integrated leads. As shown ingreater detail in the attached drawing figures, the sensors include adiaphragm structure and the integrated lead structure. In embodiments,at least an insulating polymer layer is common to both the diaphragm andlead structures, and in embodiments the polymer layer and optionallystructures such as traces on the polymer layer can be formed by the sameprocess steps at the same times. At least portions of the traces on thelead structures and portions of the electrodes on the diaphragmstructures can be formed by the same process steps in embodiments. Inother embodiments the polymer layer portions of the diaphragm and leadstructures are not common, and can be formed separately (even ifadjacent to one another).

The lead structures can be flex structures or flex circuits, and can beformed on base materials including non-metals (e.g., ceramic or otherinsulating materials) and metals such as stainless steel or other springmetals. The diaphragm structures are also flexible in embodiments. Asshown, in embodiments the diaphragm structures include: two polymer(e.g., Kapton) members, one polymer and one metal (e.g., stainlesssteel) member, or two metal members. Other embodiments include diaphragmstructures formed from other materials such as ceramics.

The sensors can be manufactured by conventional additive deposition,semi-additive and/or subtractive processes such as wet (e.g., chemical)and dry (e.g., plasma) etching, electroplating and electroless platingand sputtering processes in connection with photolithography (e.g., useof patterned and/or unpatterned photoresist masks), and laminationprocesses (e.g., by the application adhesive and/or through theapplication of pressure and/or heat). Mechanical forming methods (e.g.,using punches and forms) can be used. Adhesive and other polymer layerscan be coated and cured, or cut from a sheet and laminated, to adjacentlayers. Additive and subtractive processes of these types are, forexample, known and used in connection with the manufacture of disk drivehead suspensions on stainless steel or other bases or substrates(including non-metal bases), and are disclosed generally in thefollowing U.S. patents, all of which are incorporated herein byreference for all purposes: Bennin et al. U.S. Pat. No. 8,885,299entitled Low Resistance Ground Joints for Dual Stage Actuation DiskDrive Suspensions, Rice et al. U.S. Pat. No. 8,169,746 entitledIntegrated Lead Suspension with Multiple Trace Configurations, Hentgeset al. U.S. Pat. No. 8,144,430 entitled Multi-Layer Ground PlaneStructures for Integrated Lead Suspensions, Hentges et al. U.S. Pat. No.7,929,252 entitled Multi-Layer Ground Plane Structures for IntegratedLead Suspensions, Swanson et al. U.S. Pat. No. 7,388,733 entitled Methodfor Making Noble Metal Conductive Leads for Suspension Assemblies,Peltoma et al. U.S. Pat. No. 7,384,531 entitled Plated Ground Featuresfor Integrated Lead Suspensions.

In embodiments, structures such as traces, electrodes and/or straingauges can be formed on an insulating polymer layer that is common tothe diaphragm and lead structures, and the insulating polymer layer canbe laminated to other components of the diaphragm structure (or a layerof material from which such other diaphragm components are formed) afterthose structures (e.g., traces and/or electrodes and/or strain gauges)are formed. In other embodiments, the common insulating polymer layercan be formed on other components of the diaphragm structure (or a layerof material from which such other diaphragm components are formed)before structures such as the traces, strain gauges and/or electrodesare formed on the common insulating polymer layer. The polymer layer andstructures (e.g., traces and/or electrodes) thereon can be formed fromlaminated materials by subtractive processes or by additive processes ofthe types described above. Via-type electrical connections such as thoseformed by plating, solder or conductive adhesive can be used toelectrically connect the traces to other electrical structures (e.g.,electrodes and/or stainless steel structures) through openings in thepolymer layers. Other embodiments (not shown) include jumpers thatextend over or around an edge of portions of the devices to electricallyinterconnect structures. Bonding/joining techniques that can be used inaddition to those expressly mentioned below includes non-conductiveepoxy, conductive epoxy, solder/sintering, laser/resistance welding,crimping/mechanical forming and laser lamination. Although embodimentsare described as having stainless steel components for the structural(e.g., base) member, other material and methods such as plasticinjection molding polymers and ceramics are used in other embodiments.These materials can be selectively metalized to facilitate fabricationof the capacitor plates and/or conductive routings, or to facilitateother joining techniques.

FIGS. 1A, B, C, D, E and F are top, bottom, side, distal end, proximalend and detailed sectional isometric views of a sensor 10 in accordancewith embodiments of the invention. Sensor 10 is a single diaphragm,partial etched cavity device, and can be used to sense relatively lowpressures. As shown, the sensor 10 includes a diaphragm structure 12 andan integrated lead structure 14 that extends from the diaphragmstructure. Diaphragm structure 12 includes a base 16 having a voidregion or cavity 18. In embodiments, the base 16 is metal such asstainless steel (SST), and the cavity 18 is a partial etched cavity. Inthese embodiments, the metal base can function as a first electrode. Inother embodiments the base can be formed from other materials such asceramic materials, and an electrode can be located on the base in thecavity. A flexible and insulating polymer layer 20 includes a diaphragmportion 22 on the base 16 and over cavity 18, and a lead portion 24 onthe lead structure 14. The diaphragm portion 22 and lead portion 24 ofthe polymer layer 20 are common in the illustrated embodiment, andinclude an adhesive layer 26 (optionally acrylic adhesive) and adielectric layer 22. A second electrode 30 is located on the diaphragmportion 22 of the polymer layer 20. Leads or traces 32A and 32B extendalong the lead portion 24 of the polymer layer 20. Lead 32A iselectrically connected to the second electrode 30. Lead 32B iselectrically connected to the first electrode (e.g., the base 16 inembodiments shown in FIGS. 1A-F) by a conductive via 34 through thepolymer layer 20. In embodiments, the second electrode 30 is a sputteredmetal layer, and can be formed during the same process step as a seedlayer for the traces 32A and 32B. A polymer or other coating layer 40can be applied over all or portions of the sensor to encapsulate thedevice. Traces 32A and 32B can include a plated metal layer on the seedlayer. Applications of sensor 10 include, for example, bodily fluidpressure, blood, intraocular and neural sensing. The area of the firstand/or second electrodes and/or cavity 18 and other features of thesensor 10 can be adapted to determine the pressure and sensitivity ofthe device.

FIGS. 2A-2N and FIGS. 3A-3I illustrate sequences of process steps thatcan be used to manufacture embodiments of sensor 10. In particular, FIG.2A shows a stainless steel (SST) layer 2000. FIG. 2B shows a stainlesssteel layer 2000 and an edge 2002 of the layer. FIG. 2C shows an etchedcavity 2004 in the stainless steel layer 2000. FIG. 2D is a detailedillustration of the stainless steel layer 2000 and etched cavity 2004.FIG. 2E illustrates a polymer layer 2006 applied to the stainless steellayer 2000. FIG. 2F illustrates the polymer layer 2006 (including anadhesive layer) on the etched stainless steel layer 2000. FIG. 2Gillustrates an etched perimeter/boundary 2008 and formed via opening2010. FIG. 2H is a detailed illustration showing the via opening 2010.FIG. 2I shows plated traces 2012 and optionally electrode. A via contactcan be formed on the structure shown in FIG. 2I. FIG. 2I also showssputtered seed layer 2014 for electrodes and traces. FIG. 2J shows viacontact (plated) 2016, plated traces 2018 and seed layer 2020. FIG. 2Kshows an applied covercoat and/or encapsulant. FIG. 2L shows a structurehaving covercoat/encapsulant 2022. FIG. 2N shows the stainless steellayer 2000 and etching/forming the stainless steel base. FIG. 3A showsthe stainless steel base layer. FIG. 3B shows the stainless steel cavitypartial etch. FIG. 3C shows the laminated dielectric/adhesive. FIG. 3Dshows the laser cut via to stainless steel. FIG. 3E shows the sputteredseed layer. FIG. 3F shows the plated conductor traces. FIG. 3G shows theetched seed layer. FIG. 3H shows a coated/etched dielectric covercoat.FIG. 3I shows the etched base stainless steel.

FIGS. 4A, B, C, D, E and F are top, bottom, side, distal end, proximalend and detailed sectional isometric views of a sensor 110 in accordancewith embodiments of the invention. Sensor 110 is a dual diaphragm,welded and etched device in embodiments, and can be used to senserelatively low pressures. As shown, the sensor 110 includes a diaphragmstructure 112 and an integrated lead structure 114. Diaphragm structure112, which has a first diaphragm portion 111 and a second diaphragmportion 113, include a ring or other shaped base member 116 defining avoid region or cavity 118. In the illustrated embodiment the base member116 is formed from first and second sections 115 and 117, respectively,which can be stainless steel (SST). A flexible and insulating polymerlayer 120 includes a first diaphragm portion 122 on the first section115 of the base member 116 and over cavity 118 (i.e., on a firstdiaphragm portion 111), and a lead portion 124 on the lead structure114. The diaphragm portion 122 and lead portion 124 of the polymer layer120 are common in the illustrated embodiment. A first electrode 129 islocated on the first diaphragm portion 111, and is on the side of thepolymer layer 120 opposite the cavity 118 in the illustrated embodiment.In other embodiments the first electrode 129 is on the side of thepolymer layer 120 facing the cavity 118. A first lead or trace 132Aextends over the polymer layer 120 from the lead structure 114 to thediaphragm structure 112, where it electrically connects to the firstelectrode 129. Second lead or trace 132B extends over the polymer layer120 from the lead structure 114 to the diaphragm structure 112, where itelectrically connects to the first section 115 of the base member 116 bya conductive via 134 through the polymer layer 120. In embodiments, thefirst electrode 129 is a sputtered metal layer, and can be formed duringthe same process step as a seed layer for the traces 132A and 132B. Apolymer or other cover coat or coating layer 140 can be applied over allor portions of the sensor to encapsulate the device. Traces 132A and132B can include a plated metal layer on the seed layer.

A second diaphragm portion 123 includes an insulating polymer layer 150on the second section 117 of the base member 116 and over cavity 118. Asecond electrode 130 is located on the second diaphragm portion 123, andis on the side of the polymer layer 150 facing the cavity 118. Thesecond electrode 130 also extends into contact with the section 117 ofthe base member 116 in this embodiment. First and second sections 115and 117 of the base member 116 are joined (e.g., by welds such as 131 orconductive adhesive). The second electrode 130 is electrically connectedto the trace 132B through the via 134 and the base member 116 (oroptionally other structures). In other embodiments, the second electrode130 is located on the side of the polymer layer 150 opposite the cavity118, and is electrically connected to a trace such as 132B by othercontact structures. In embodiments, the first diaphragm portion 122 andlead structure 114 are formed separately from the second diaphragmportion 123, and assembled together by joining the sections 115 and 117of the base member 116 as described above. All or portions of the sensor110 can be encased or encapsulated (e.g., by sputtering) in abio-compatible or other material such as Ti and/or SiO2 to prevent orminimize moisture/gas migration into the cavity 118. Alternatively tothe covercoat layer 140, or in addition to the covercoat layer orencapsulating layer, a gas and/or moisture barrier can be formed byencapsulating all or portions of the sensor 110 in polymer such asParylene. Sensor 110 can be relatively small (e.g., compared to sensor10), yet provide equivalent sensitivity. Design variables can includethe thicknesses and sizes of the base member sections, polymer layersand covercoat.

FIGS. 5A-5S and FIGS. 6A-6K illustrate sequences of process steps thatcan be used to manufacture embodiments of sensor 110. In particular,FIG. 5A shows the stainless steel layer 2030. FIG. 5B shows thestainless steel layer 2030 and the edge 2032 of the stainless steellayer. FIG. 5C shows applying/forming the polymer layer. FIG. 5D showsthe polymer layer 2034. FIG. 5E shows forming the boundary of thepolymer layer and via opening 2036 on the first diaphragm portion andlead structure. FIG. 5F shows the via opening 2036. FIG. 5G showssputtering the seed layer 2038. FIG. 5H shows the seed layer 2038. FIG.5I shows plating the traces. FIG. 5K shows applying the cover coat. FIG.5M shows forming the base member of the first diaphragm portion of thediaphragm structure. FIG. 50 shows manufacturing the second diaphragmportion of the diaphragm structure and attaching to the first diaphragmportion and lead structure. FIG. 5P shows the electrode 2040. FIG. 5Qshows the weld 2042. FIG. 5R shown encapsulating the device. FIG. 6Ashows the base metal (stainless steel or other). FIG. 6B shows coatingthe dielectric (photosensitive or other). FIG. 6C shows etching thedielectric. FIG. 6D shows sputtering the seed layer. FIG. 6E showsplating conductor traces. FIG. 6F shows etching the seed layer. FIG. 6Gshows coating/etching the dielectric covercoat. FIG. 6H shows etchingthe stainless steel. FIG. 6I shows sputtering the seed layer on thelower diaphragm and mount (made similarly to the top portion withoutplated conductors/covercoat). FIG. 6J shows laser welding. FIG. 6K showsapplying a moisture/gas barrier (PVD Parylene or sputtered metallic).

FIGS. 7A, B, C, D, E, F and G are top, bottom, side, distal end,proximal end, isometric and detailed sectional isometric views of asensor 210 in accordance with embodiments of the invention. Sensor 210can be used in relatively high pressure applications. As shown, thesensor 210 includes a diaphragm structure 212 and an integrated leadstructure 214. Diaphragm structure 212 includes a base 216. Inembodiments, base 216 is metal such as stainless steel (SST). A flexibleand insulating (i.e., dielectric) polymer layer 220 includes a diaphragmportion 222 on or over the base 216 and a lead portion 224 on or overthe lead structure 214. The diaphragm portion 222 and lead portion 224of the polymer layer 220 are common in the illustrated embodiment. Afirst electrode 229 is located on the side of the polymer layer 220opposite the base 216. Leads or traces 232A and 232B extend along thelead portion 224 of the polymer layer 220. Lead 232A is electricallyconnected to the first electrode 229. The diaphragm structure 212 alsoincludes a member 230 over the diaphragm portion 222 and joined to thebase 216 and any intervening layers (e.g., polymer layer 220 in theillustrated embodiment) by an adhesive insulating polymer layer 219. Acavity 218 is defined in the diaphragm structure 212 between the base216 (and electrode 229) and the member 230. In embodiments, the member230 is metal such as stainless steel. In these embodiments the member230 can function as a second electrode. Lead 232B is electricallyconnected to the second electrode (e.g., the member 230 in embodimentsshown in FIGS. 7A-F) by a conductive via 234 through the adhesivepolymer layer 219. In other embodiments, the member 230 can be formedfrom other materials such as ceramic materials, and an electrode can belocated on the member in the cavity. In embodiments, the first electrode229 includes sputtered and optionally plated metal layers, and can beformed on the polymer layer 220 during the same process steps as thetraces 232A and 232B. Covercoat and/or encapsulation layers such asthose described above can be applied over all or parts of the sensor210. Sensor 210 offers a wide range of design variables that can beadvantageously used to determine parameters such as the sensitivitiesand ranges of pressures of the device. For example, the thicknesses,including those of partial etched regions, of the base 216 and themember 230 can be determined. Thickness of the sputtered and/or platedconductor layers forming the electrode 229 and traces 232A and 232B,polymer layer 220 and/or adhesive polymer layer also can be determinedfor these purposes. The illustrated embodiments include a button on themember 230, and the height of the button can be used to self-limitdeflection of the member. The stiffness of the diaphragm structure 212can remove drift due to temperature and background pressure changes.Embodiments with a rigid base 216 can be relatively efficiently andeffectively mounted to other structures. In yet other embodiments theelectrode 229 can be replaced with a partial-etched mesa on the base216, and the base 216 used as an electrode.

FIGS. 8A-8P and FIGS. 9A-9L illustrate sequences of process steps thatcan be used to manufacture embodiments of sensor 210. In particular,FIG. 9A illustrates the base stainless steel. FIG. 9B illustrates apartial etch. FIG. 9C illustrates coating the dielectric. FIG. 9Dillustrates etching/developing the dielectric. FIG. 9E illustratessputtering the seed layer. FIG. 9F illustrates plating the conductors.FIG. 9G illustrates etching the seed layer. FIG. 9H illustrateslaminating pre-cut sheet adhesive. FIG. 9I illustrates applyingconductive epoxy to a via hole. FIG. 9J illustrates laminating the topstainless steel/cure adhesive and epoxy. FIG. 9K illustrates theoptional step of partial etching a force concentrator feature. FIG. 9Lillustrates etching the stainless steel and laser cutting sheetadhesive.

FIGS. 10A, B, C, D, E and F are top, bottom, side, distal end, proximalend and isometric views of a cluster sensor 310 in accordance withembodiments of the invention. FIGS. 11A-11O and 12A-12I illustratesequences of process steps that can be used to manufacture embodimentsof sensor 310. Sensor 310 is a tri-axis sensor that includes multiple(i.e., three) sensors similar in structure and operation to those ofsensor 210 that are integrated into a common diaphragm structure 312 andlead structure 314. Certain features of sensor 310 that are similar tothose of sensor 210 are indicated by similar reference numbers. Inembodiments, sensor 310 has a single stainless steel (SST) diaphragmstructure and is capable of being used in relatively high pressureapplications. Embodiments of the sensor includes a common base 316 and apolymer layer 320 having electrodes 3291, 3292 and 3293, and traces332A1, 332A2, 332A3 and 323B. Trace 323B can be coupled to the diaphragmmember 330 by a conductive via. Covercoat and/or encapsulation layerssuch as those described above can be applied over all or parts of thesensor 310. Sensor 310 can be manufactured using processes similar tothose described above in connection with sensors 10, 110 and 210.

In particular, FIG. 11A shows the stainless steel layer 2050. FIG. 11Bshows the stainless steel layer 2050 and the edge 2052. FIG. 11C showspartial etching the stainless steel layer to form mesas for electrodes.FIG. 11D shows applying the polymer layer 2054. FIG. 11F shows formingelectrodes on mesas and traces to electrodes. FIG. 111 shows aconductive via 2056 through an opening and applying an adhesive layerand forming a via opening. FIG. 11J shows applying an upper stainlesssteel layer. FIG. 11K shows the upper stainless steel layer 2058. FIG.11L shows partial etching the stainless steel layer to form buttons.FIG. 11O shows removing excess from the upper layer. FIG. 12A shows thebase stainless steel. FIG. 12B shows the optional step of partialetching the stainless steel. FIG. 12C shows coating/etching thedielectric layer. FIG. 12D shows sputtering the seed layer and platingconductors. FIG. 12E shows laminating pre-cut sheet adhesive. FIG. 12Fshows laminating top stainless steel and curing adhesive/epoxy. FIG. 12Gshows partial etching force concentrator features. FIG. 12H showsetching stainless steel layers. FIG. 12I shows laser cutting sheetadhesive to final shape.

FIGS. 13A, B, C, D, E and F are top, bottom, side, distal end andproximal end views of a cluster sensor 410 in accordance withembodiments of the invention. Similar to sensor 310, sensor 410 includesmultiple (i.e., four) sensors similar in structure and operation tothose of sensors 210 that are integrated into a common diaphragmstructure 412 and lead structure 414. Features of at least some of theindividual sensors in the sensor 410 have different sizes (e.g.,diameters and/or thicknesses), enabling the different sensors to operateat different sensitivities. Certain features of sensor 410 that aresimilar to those of sensor 210 are indicated by similar referencenumbers. Covercoat and/or encapsulation layers such as those describedabove can be applied over all or parts of the sensor 410. Sensor 410 canbe manufactured using processes similar to those described above inconnection with sensors 10, 110, 210 and 310.

FIGS. 14A-14Q and 15A-15J illustrate sequences of process steps that canbe used to manufacture embodiments of sensor 410. In particular, FIGS.14A and 14B illustrate the stainless steel layer. FIG. 14C showsapplying the polymer layer 2060. FIG. 14E shows forming electrodes andtraces. FIG. 14G shows applying the adhesive layer and forming viaopenings. FIG. 141 shows a via contact 2062 and plating the via contact.FIG. 14J shows the via contact 2062. FIG. 14K shows applying the upperstainless steel layer. FIG. 14M shows partial etching the upperstainless steel layer. FIG. 140 shows removing excess upper stainlesssteel layer and lower stainless steel layer. FIG. 15A shows the basestainless steel. FIG. 15B shows coating the dielectric layer. FIG. 15Cshows sputtering the seed layer. FIG. 15D shows plating conductors. FIG.15E shows etching the seed layer. FIG. 15F shows laminating pre-cutsheet adhesive. FIG. 15G shows applying conductive epoxy to the viahole. FIG. 15J shows etching stainless steel and laser cutting sheetadhesive.

FIGS. 16A, B, C, D, E and F are top, bottom, side, distal end, proximalend and detailed sectional isometric views of a sensor 510 in accordancewith embodiments of the invention. Sensor 510 is a dual diaphragm devicehaving an adhesive spacer with interior seed layer encapsulation andelectrodes. Sensor 510 is similar to sensor 110, and similar featuresare identified with similar reference numbers. As shown, the sensor 510includes a diaphragm structure 512 and an integrated lead structure 514.Diaphragm structure 512, which has a first diaphragm section or portion511 and a second diaphragm section or portion 513, includes a ring orother shaped base member 516 defining a void region or cavity 518. Inthe illustrated embodiment the base member 516 is formed from first andsecond sections 515 and 517, respectively, which can be stainless steel(SST). A flexible and insulating polymer layer 520 includes a firstdiaphragm portion 522 on the first section 515 of the base member 516and over cavity 518 (i.e., on a first diaphragm portion 511), and a leadportion 524 on the lead structure 514. The diaphragm portion 522 andlead portion 524 of the polymer layer 520 are common in the illustratedembodiment. A first electrode 529 is located on the first diaphragmportion 511, and is on the side of the polymer layer 520 facing thecavity 518 in the illustrated embodiment. In other embodiments the firstelectrode 529 is on the side of the polymer layer 520 opposite thecavity 518. A first lead or trace 532A extends over the polymer layer520 from the lead structure 514 to the diaphragm structure 512, where itelectrically connects to the first electrode 529 (through the firstsection 515 of the base member 516). Second lead or trace 532B extendsover the polymer layer 520 from the lead structure 514 to the diaphragmstructure 512, where it electrically connects to the second section 517of the base member 116 by a conductive via 534 through the polymer layer520, first section 515 and adhesive and insulating polymer layer 519. Inembodiments, the first electrode 529 is a sputtered metal layer. Apolymer or other covercoat or coating layer 540 can be applied over allor portions of the sensor to encapsulate the device. Traces 532A and532B can include a plated metal layer on the seed layer.

A second diaphragm portion 513 includes an insulating polymer layer 550on the second section 517 of the base member 516 and over cavity 518. Asecond electrode 530 is located on the second diaphragm portion 513, andis on the side of the polymer layer 550 facing the cavity 518. Thesecond electrode 530 also extends into contact with the section 517 ofthe base member 516 in this embodiment. First and second sections 515and 517 of the base member 516 are joined by the adhesive polymer layer519. The second electrode 530 is electrically connected to the trace532B through the via 534 (which includes conductor material 541 such assolder or conductive adhesive). In other embodiments, the secondelectrode 530 is located on the side of the polymer layer 520 oppositethe cavity 518, and is electrically connected to a trace such as 532B byother contact structures. In embodiments, the first diaphragm portion522 and lead structure 514 are formed separately from the seconddiaphragm portion 513, and assembled together by joining the sections515 and 517 of the base member 516 through the use of adhesive polymerlayer 519. All or portions of the sensor 510 can be encased orencapsulated (e.g., by sputtering) in a bio-compatible or other materialsuch as Ti and/or SiO2 to prevent or minimize moisture/gas migrationinto the cavity 518. Alternatively to the covercoat layer 540, or inaddition to the covercoat layer or encapsulant layer, a gas and/ormoisture barrier can be formed by encapsulation all or portions of thesensor 510 in polymer such as Parylene. Design variables can include thethicknesses and sizes of the base member sections, polymer layers andcover coat.

FIGS. 17A-17MM and 18A-18N illustrate sequences of process steps thatcan be used to manufacture embodiments of sensor 510. In particular,FIG. 17A shows the stainless steel layer 2070 and the first diaphragmsection (formed with the lead structure). FIG. 17C shows applying thepolymer layer. FIG. 17E shows the first diaphragm section. FIG. 17E alsoshows patterning the polymer layer and forming via openings. FIG. 17Hshows sputtering the seed layer 2072. FIG. 17J shows plating traces andetching the seed layer. FIG. 17R shows applying the dielectriccovercoat. FIG. 17U shows the first diaphragm section and lead section,etching the stainless steel layer, and a stainless steel island 2074.FIG. 17V shows the stainless steel island 2074. FIG. 17W shows thestainless steel island 2074 for electrical contact to the seconddiaphragm section. FIG. 17DD shows the adhesive layer 2076 andlaminating the adhesive layer. FIG. 17EE shows the adhesive layer 2076.FIG. 17GG shows the second diaphragm section 2078 and laminating thesecond diaphragm section to the first diaphragm section. FIG. 17HH showsthe second diaphragm section 2078 and the lead structure 2080. FIG. 17JJshows applying a conductor 2082 to the via to the second diaphragmsection. FIG. 18A shows the base stainless steel for the first diaphragmsection. FIG. 18B shows applying dielectric and the polymer layer 2084common to the diaphragm and lead structures. FIG. 18C shows etching anddeveloping dielectric. FIG. 18D shows sputtering the seed layer. FIG.18E shows plating conductor traces. FIG. 18F shows etching the seedlayer, trace 2086 to the first diaphragm electrode, via contact 2088 tothe first diaphragm electrode (through the stainless steel layer) and anopening 2090 for a via to the second diaphragm structure. FIG. 18G showscoating a dielectric covercoat. FIG. 18H shows etching/developing adielectric covercoat. FIG. 18I shows a via opening 2092 for contact tothe second diaphragm structure and stainless steel island 2094. FIG. 18Jshows sputtering the cavity seed layer and sputtered conductorlayer/electrode 2096 of the first diaphragm structure. FIG. 18K showsselectively etching the seed layer. FIG. 18L shows the adhesive layer2098 and laminating the adhesive layer. FIG. 18M shows laminating thelower diaphragm (made similarly to the top portion withoutconductor/covercoat) and trace 3000 to the first diaphragm structure.FIG. 18N shows applying solder/conductive epoxy, a trace 3002 to anelectrode on the second diaphragm section, sputtered conductor layer3004 that is an electrode of the second diaphragm section, and stainlesssteel 3006.

FIGS. 19A, B, C, D, E and F are top, bottom, side, distal end, proximalend and detailed sectional isometric views of a strain gauge-type sensor610 in accordance with embodiments of the invention. As shown, sensor610 includes a diaphragm structure 612 and an integrated lead structure614 that extends from the diaphragm structure. Diaphragm structure 612includes a base 616 having a void region or cavity 618. In embodiments,the base 616 is metal such as stainless steel (SST), and is formed fromstainless steel members 615 and 617. A pair of strain gauge members 660and 662 (other embodiments have more or fewer strain gauge members) areformed on a polymer layer 620 having diaphragm portion 622 and leadportion 624. Leads or traces 632 extend over the lead portion 624 of thepolymer layer 620 and are electrically coupled to the strain gaugemembers 660 and 662. As shown, strain gauge member 660 is located on amoving portion of the diaphragm structure 612 (e.g., over the cavity618). Sensor 662 is located on a non-moving or static region of thesensor 610 (e.g., not over the cavity 618), and is shown closer to thelead structure 614 in the illustrated embodiment. Sensor 610 can bemanufactured using processes similar to those described above inconnection with sensors 10, 110, 210, 310, 410 and 510. FIGS. 20A-20Uillustrate embodiments of a sequence of process steps that can be usedto manufacture sensor 610.

FIGS. 21A and 21B are isometric views of a sensor 710 having flipped twotrace assemblies with welded base members in accordance with embodimentsof the invention. FIG. 21A illustrates a first or upper side of thesensor 710, and FIG. 21B illustrating an opposite second or lower sideof the sensor. Sensor 710 includes a diaphragm structure 712 and anintegrated lead structure 714 that extends from the diaphragm structure.FIGS. 22A and 22B are exploded views of sensor 710 in accordance withembodiments, with FIG. 22A illustrating the sensor components from theirupper or top sides, and FIG. 22B illustrating the sensor components fromtheir lower or bottom sides. In the embodiments shown in FIGS. 22A and22B, the sensor 710 includes a first or upper component or assemblyhaving a diaphragm portion 711 and a lead portion 713, and a second orlower component or assembly having a diaphragm portion 715 and a leadportion 717. FIGS. 23A and 23B are sectional isometric views of sensor710 in accordance with embodiments of the invention, with the sectionlines extending through the diaphragm structure 72. FIG. 23A is a viewlooking down from slightly above, and FIG. 23B is a view looking up fromslightly below (termination leads visible).

The diaphragm portion 711 of the upper assembly includes a diaphragmmember formed from non-metals or metals such as stainless steel, andincludes an outer or base portion 730 and an inner, moving portion 733attached to the base portion by spring arms 734. In embodiments, themember of the diaphragm portion 711 is formed as an integral member froma single sheet of spring metal such as stainless steel (e.g., byetching). A first conductive electrode 729 is located on an interiorsurface of the moving portion 732, and is electrically isolated from thediaphragm member (in embodiments where the member is formed ofconductive material) by a polyimide or other insulating layer 720. Leadportion 713 includes a base member that can be formed from theinsulating layer 720. A lead or trace 732 extends from the lead portion713 to the electrode 729, including a length that traverses a spring arm734 in the illustrated embodiment, and is electrically isolated from thediaphragm member by the insulating layer 720. In other embodiments (notshown), the trace extends to the electrode 729 across the spring armsand gaps between the spring arms.

The diaphragm portion 715 of the lower assembly can be formed fromnon-metals or metals such as stainless steel, and includes a baseportion 750 that is shown as an annular member, insulating layer 752 anda second electrode 754 on a side of the insulating layer opposite thebase portion. Lead portion 717 includes a base that can be formed fromthe insulating layer 752, and a lead or trace 756 that extends to theelectrode 754. As shown in FIGS. 23A and 23B, the base portion 730 ofthe diaphragm portion 711 is joined to the base portion 750 of thediaphragm portion 715 (e.g., by welds or adhesive at their peripheries)to define a void region or cavity 718 in the diaphragm structure 712. Asshown in FIG. 22A, the base portion 750 of the lower assembly caninclude a gap 760 through which the lead portion 713 of the upperassembly can extend. Adhesive or other material can be applied to sealany space between the gap 760 and lead portion 713 following assembly ofthe upper and lower assemblies. In other embodiments the diaphragmstructure 712 is not sealed. Embodiments can include an insulating covercoat over portions or all of the structures such as electrodes 729 and754 and traces 732 and 756 formed from the conductive material layer.Such a cover coat can prevent electrical shorting, sensor damage and outof range capacitance if the applied pressure creates interferencebetween the electrodes. The cover coat can also enhance stability of thesensor 710 by preventing electrolytic and/or oxidative degradation ofthe conductor surfaces.

The configuration of the diaphragm structure 712 (e.g., the suspensionor support of the moving portion 372 by the spring arms 734) helpsmaintain parallelism between the electrodes 729 and 754 during operationof the sensor 710. In particular, spring bias can be reduced from theinsulating layer 720 and conductor layer of the trace 732 on the springmetal layer when the trace 732 extends along a spring arm 734. Accuracyand repeatability of measurements are can thereby be increased.Stiffness of the spring arms can be tuned to desired pressure ranges. Byway of non-limiting example, in embodiments the outside diameters of theelectrodes 729 and 754 are about 0.44 mm, and the outside diameters ofthe base portions 730 and 750 are about 1.04 mm. Traces 732 and 756 canbe about 0.03 mm in width. Stainless steel layer portions can be about35 μm thick. The insulating layer can be polyimide, and about 710 μmthick. Any cover coat can be about 5 μm thick. Structures such as theelectrodes 729 and 754 and traces 732 and 756 formed in the copper orother conductor layer can be about 10 μm thick. The diaphragm structure712, or the portions 711 or 715, can be encased in epoxy or fixed toother structures to which the sensor is mounted.

FIG. 24 is an isometric view of an integrated lead and can sensor 810having a diaphragm structure 812 and integrated lead structure 814 inaccordance with embodiments of the invention. As shown, sensor 810includes a circuit or trace member 813 and a can 850. FIG. 25 isdetailed isometric view, with portions of the can 850 broken away toexpose portions of the trace member 813 within the diaphragm structure812. FIG. 26 is a detailed sectional view of a portion of the diaphragmstructure 812. Trace member 813 includes a diaphragm portion 811 and alead portion 803. The trace member 813 is formed from a metal (e.g.,stainless steel) diaphragm member or base 826, polyimide or otherinsulating layer 820, and a conductor layer 828. The diaphragm portion811 of trace member 813 includes an electrode 829 in the conductor layer828 over and electrically isolated from the base 826 by insulating layer820. Gold and/or nickel can be plated on the electrode 829 and/or otherportions of the conductor layer 828 in embodiments. The lead structure814 of trace member 813 includes a trace 832 in the conductor layer 828that extends to the electrode 829. Trace 832 is electrically isolatedfrom the base 826 by the insulating layer 820. In embodiments, thediaphragm base 826 includes one or more annular recesses (which can bepartially etched) to enable motion of the electrode 829 and adjacentportion of the base during operation of the sensor 810 (i.e. byproviding an accordion-like effect). Can 850 is a metal member (e.g.,stainless steel) in the illustrated embodiment, and defines a void orcavity 818 in the diaphragm structure 812. The can 850 is mechanicallyand electrically connected to the base 826 (e.g., by welds or conductiveadhesive) and functions as a second electrode, and the base layer 826 ofthe lead structure 814 functions as a return ground path (i.e., as asecond electrical lead). As shown in FIG. 84, the lead structure extendsfrom a gap 860 in the can 850. The gap 860 is sealed in embodiments.

FIG. 27 is an isometric and partial cut-away illustration of a sensor810′ in accordance with embodiments of the invention. Sensor 810′ has alayer of material 860 on the electrode 829′. Material 860 can be amaterial having a relatively high dielectric constant and/or relativelylow durometer elastomer material to partially fill the cavity 818′ andallow for expansion under compression. In embodiments, for example,material 160 is silicone loaded with TiO2. Other than the material 160,sensor 110′ can be the same as or similar to the sensor 110 describedabove.

FIGS. 28-30 are isometric illustrations of a sensor 810″ in accordancewith embodiments of the invention. Sensor 810″ includes a diaphragmstructure 812″ and integrated lead structure 814″. Integrated leadstructure 814″ of trace member 813″ includes a trace 833 in theconductor layer 828″ that extends to the diaphragm structure 812″ andelectrically connects to the can 850″ (e.g., by conductive adhesive)that functions as an electrode. Like trace 832″, trace 833 iselectrically isolated from the base 826″ by insulating layer 820″. Otherthan the lead structure associated with trace 833, sensor 810″ can bethe same as or similar to sensors 810 and 810′ described above (e.g.,sensor 810″ can have a layer of high dielectric constant elastomermaterial on the electrode 829″).

FIG. 31 is sectional isometric view of a sensor 910 having a diaphragmstructure 912 and integrated lead structure 914 in accordance withembodiments of the invention. FIG. 32 is an exploded view of the sensor910 shown in FIG. 31. Sensor 910 includes a two trace members 913, eachhaving a diaphragm portion 911 and a lead portion 903. Trace members 913can be the same as or similar to trace member 813 described above, andinclude a trace 932 coupled to an electrode 929 in a conductor layer928, with the conductor layer electrically isolated from the base layer926 by insulator layer 920. Trace members 913 are joined (e.g., by weldsor adhesive), with the electrodes 929 facing one another, to a spacer965 to define a void or cavity 918. Spacer 956 can be metal, ceramic,polymer or other materials.

FIG. 33 is an isometric view of a sensor 1010 having a diaphragmstructure 1012 and integrated lead structure 1014 in accordance withembodiments of the invention. Sensor 1010 includes two trace members1013A and 1013B, each having a diaphragm portion 1011 and a lead portion1003. FIG. 34 is a view of the sensor 1010 shown in FIG. 33, with thetrace member 1013A removed. Trace member 1013A can be the same as orsimilar to trace member 813 described above. Trace member 1013B can besimilar to trace member 813 described above, but as perhaps best shownin FIG. 34, the base member 1026 includes a recess or pocket (e.g.,etched in a layer of stainless steel) to provide an annular wall 1027. Aseparate spacer component such as 965 described in the embodiment ofFIGS. 31 and 32 is therefore not needed to provide the cavity 1018.

FIGS. 35, 36, 37A, 37B, 38A and 38B illustrate and describe a sensor1100 in accordance with yet additional embodiments of the invention. Asshown, the sensor 1100 includes a diaphragm structure 1112 and anintegrated lead structure 1114. Portions of the sensor 1100 includingthe diaphragm structure 1112 and integrated lead structure 1114 includea circuit or trace member 1113. A member 1150 such as a stainless steeldisk that functions as an electrode is mounted to the trace member 1113.A stainless steel disks is attached to complete the structure shown inFIG. 36, which is a top view. FIG. 35 is a cross section, showing thetop stainless steel 1120, TSA+ ring stainless steel 1122, TSA+ coppervia 1124 and capacitor plate 1126, and TSA+ dielectric 1128. FIGS. 37A(bottom view) and 37B (top view) show just the TSA+ base component,including copper (CU) 1130 and polyimide (PI) 1132. Via connection 1134is made to stainless steel toroid 1136. FIGS. 38A (exploded top view)and 38B (top view) show the stainless steel disk attached to completethe sensor.

FIGS. 39A and 39B are isometric illustrations of a sensor 1210 inaccordance with still other embodiments of the invention, showingopposite sides of the sensor. FIGS. 40 and 41 are exploded views of thesensor 1210, taken generally from the side shown in FIG. 39A. FIGS. 42and 43 are exploded views of the sensor 1210, taken generally from theside shown in FIG. 39B. In the illustrated embodiment, sensor 1210 is acapacitive device that includes a first or top circuit portion 1211 witha springboard 1213, a second or fixed circuit portion 1215, and a basebacker plate 1217, which can be stainless steel or other sufficientlyrigid material. Other embodiments do not include the backer plate 1217(e.g., in embodiments where the sensor 1210 is mounted to a rigidsurface). The sensor 1210 includes a diaphragm structure 1212 includingspringboard 1213, and an integrated lead structure 1214 that extendsfrom the diaphragm structure. Each of the top circuit portion 1211 andfixed circuit portion 1215 includes a diaphragm portion and anintegrated lead portion in the illustrated embodiment. Diaphragmstructure 1212 includes a base 1216 having a void region or cavity 1218.In the illustrated embodiment, the cavity 1218 is a space between arms1219 in the diaphragm portion of the fixed portion 1215. Other than theconfiguration of the springboard 1213, sensor 1210 has features similarto those of other embodiments described above.

Top circuit portion 1211 includes a metal (e.g., stainless steel) baselayer 1220, a polymer or other dielectric insulator layer 1222, aconductor (e.g., copper or copper alloy plated on a sputtered chromiumor other seed layer) layer 1224, and a polymer covercoat 1226. FIG. 45Aillustrates the conductor layer 1224 of the top circuit portion 1211,which includes an electrode portion 1224A on the springboard 1213 of thediaphragm portion, and a lead or trace portion 1224B on the integratedlead portion. The polymer layer 1222 includes a diaphragm portion thatelectrically insulates the electrode portion 1224A of the conductorlayer 1224 from the base layer 1220, and a lead portion thatelectrically insulates the lead portion 1224B of the conductor layerfrom the base layer. In the illustrated embodiment the conductor layer1224 is embedded within the covercoat 1226. Other embodiments do notinclude some or all of the covercoat 1226. The electrode portion 1224Aof the conductor layer 1224 functions as an electrode that moves withthe springboard 1213 in response to the application of force to thespringboard. The diaphragm portion and the lead portion of the polymerlayer 1222 are common, and the electrode portion 1224A and lead portion1224B of the conductor layer 1224 are common (e.g., fabricated duringthe same manufacturing steps). Arm portions 1224C and 1224D of theconductor layer 1224 maintain the height of the associated portions oftop circuit portion 1211 with respect to other components of the sensor1210.

The fixed circuit portion 1215 includes a metal or other material (e.g.,ceramic) base layer 1230, a polymer or other dielectric insulator layer1232, a conductor layer 1234, and a polymer covercoat 1236. FIG. 45Billustrates the conductor layer 1234 of the fixed circuit portion 1215,which includes an electrode portion 1234A on the diaphragm portion, anda lead or trace portion 1234B on the integrated lead portion. FIG. 44 ispartially exploded view of the sensor 1210, with the backer plate 1217shown separated from other portions of the structure and the covercoathidden to show the conductor layer 1234. The polymer layer 1232 includesa diaphragm portion that electrically insulates the electrode portion1234A of the conductor layer 1234 from the base layer 1230, and a leadportion that electrically insulates the lead portion 1234B of theconductor layer from the base layer. Embodiments of the invention havinga base layer of non-conductive material need not include the polymerlayer 1232. In the illustrated embodiment the conductor layer 1234 isembedded within the covercoat 1236. Other embodiments do not includesome or all of the covercoat 1236. The electrode portion 1234A of theconductor layer 1234 functions as an electrode. The diaphragm portionand the lead portion of the polymer layer 1232 are common, and theelectrode portion 1234A and lead portion 1234B of the conductor layer1234 are common. Arm portions 1234C and 1234D of the conductor layer1234 maintain the height of the associated portions of fixed circuitportion 1215 with respect to other components of the sensor 1210. Topcircuit portion 1211, fixed circuit portion 1215, and the backer plate1217 (in embodiments that have this element) can be joined by adhesive,welds or other structures or approaches. Features of sensor 1210 can besimilar to those of corresponding features of the other embodiments ofsensors described above, and can be manufactured using similarfabrication processes.

FIGS. 46A and 46C are top and bottom isometric views of a sensor 1310 inaccordance with additional embodiments of the invention. FIG. 46B is across sectional view of the sensor 1310. As shown, sensor 1310 is astrain gauge device that includes a springboard portion 1313 extendingfrom a static base or lead structure 1314. A first or top strain gaugecircuit 1360 is located on the first or top surface of the springboardportion 1313 and has leads 1332 that extend onto the lead structure1314. Similarly, a second or bottom strain gauge circuit 1362 is locatedon the second or bottom surface of the springboard portion 1313, and hasleads 1333 that extend onto the lead structure 1314. The stain gaugecircuits 1360 and 1362 mirror each other in embodiments. Strain gaugecircuits 1360 and 1362 and the associated leads 1332 and 1333 can beplated metal such as Constantan. In the illustrated embodiment, thespringboard and lead structure include a spring metal base layer 1316such as stainless steel, although other embodiments use other materialssuch as polymers or ceramics. The springboard portion 1313 therebyfunctions as a diaphragm structure in response to the application ofpressure or force. Both the top and bottom circuits 1360 and 1362 arearranged in a serpentine configuration such that most of the serpentinelength extends into the moving springboard portion 1313 of the basestructure or layer 1316. In embodiments such as that shown having aconductive metal base layer 1316, layers of insulating polymer 1320 canseparate the metal base layer from the circuits 1360 and 1362. Theterminals (electrical pads) on the leads 1332 and 1333 of the straingauge circuits 1360 and 1362, respectively, can be located on the staticregion of the base structure or extend further down the integrated leadstructure 1314. Sensor 1310 can be manufactured using processes similarto those described above. As with the sensors described above, thestrain gauge circuits 1360 and 1362 and associated insulating layers ofpolymer 1320 are common to the springboard (i.e., diaphragm) portion1313 and lead structure 1314.

The dual strain gauge sensor 1310 embodiment locates both the straingauge circuits 1360 and 1362 on the moving springboard region 1313 of adiaphragm structure. When the springboard region 1313 is moved ordeflected, one strain gauge element (e.g., 1360) is tensioned while theopposite side strain gauge element (e.g., 1362) is compressed. Anadvantage of the two strain gauge sensor 1310 is that the thermal output(signal error from temperature changes) can be minimized when the firstand second strain gauge elements are connected to adjacent legs of aWheatstone bridge signal processing circuit (not shown). Wheatstonebridge circuits are known and commonly used to measure the smallresistance changes (e.g., milliohms) that occur within a strain gaugeelement exposed to tension or compression forces. Sensors such as 1310can produce significantly higher signal outputs (e.g., twice as high)for a given movement displacement since both strain gauge elements areactively moved producing a similar absolute resistance changecontributing to the Wheatstone bridge signal output.

Embodiments of the invention described herein (e.g., in connection withFIGS. 21-45) can include one or more features of the sensors disclosedin the above-identified and incorporated application No. 62/290,789(i.e., the sensors described in connection with FIGS. 1-20). Similarly,one or more features of the sensors disclosed herein (e.g., inconnection with FIGS. 21-45) can be incorporated into the sensorsdisclosed in application No. 62/290,789 (i.e., the sensors described inconnection with FIGS. 1-20). For example, one or both of the spring armsupported diaphragm member and the high dielectric constant materialwithin the diaphragm structure can be incorporated into the sensorsdescribed in connection with FIGS. 1-20. Furthermore, features describedin herein in connection with embodiments (e.g., the diaphragm memberhaving spring arms, high dielectric layer material, plating and covercoat) can be incorporated into any or all other embodiments.

Embodiments of the invention have reduced capacitance offset, noise anddrift from parasitic (zero applied pressure) capacitance that existsbetween other conductors and dielectrics not within the overlapping andcompressible electrode areas within the diaphragm members. Parasiticcapacitance changes with pressure are reduced. Separation distancebetween the voltage source and sink conductors, laterally andvertically, is increased. Separation distances between source and sinkconductors and other metallic surfaces can be increased. Otherembodiments (not shown) can reduce parasitic capacitance by extendingand connecting either one or both diaphragm member metal layers to athird conductor trace routed to earth ground, supply signal ground or acapacitance bridge junction. Operation of the sensors is enhanced by theuse of high dielectric constant material between the overlapping andcompressible electrodes and low dielectric constant material (less thanor equal to the diaphragm gap material) between the conductive surfacesthat do not constrict the pressure diaphragm, the parallel conductingplates and overlapping space. Capacitance changes to applied pressureare increased. Enhancing the dielectric constant of the material betweenthe parallel conducting plates increases sensitivity to appliedpressure. Performance is enhanced by the use of a composite ofcompressible elastomer (low young's modulus or hardness) andsemi-conductive particles, such as TiO2, with large dielectric constant(e.g., 50). The number of assembled parts can kept relatively low byusing integrated circuit members formed from insulating and conductivematerial layers on a base such as spring metal.

The sensors can be incorporated into medical devices such as cathetersand endoscopes. For example the sensors can be incorporated at thedistal or leading ends of catheters and endoscopes, to sense pressureson the devices that are applied axially and/or from the sides of thedevices. In other embodiments the sensors are used in applications suchas automotive, aerospace, industrial, mineral extraction, subsea, andgeothermal. Yet other applications include positional sensors, such asdifferential force sensors to determine positions (e.g., of joysticks).The sensors can be well suited to high temperature and/or harsh orcorrosive environments. They can also be very small (e.g., thin orhaving low Z-height). For example, embodiments of the sensors can rangefrom 100 μm to 1000 μm to 5000 μm in diameter, although larger or smallsensors are contemplated. In sensors of these types the thickness of thedielectric insulating layers can range from 3-10 μm, the thickness ofthe sputtered conductor layers can range from 1-50 μm, the thickness ofstainless steel layer can range from 12-500 μm, and the traces can be asthin as 10 μm. These structures can also be made thicker or thinnerbased on factors such as available process constraints and parametersand desired characteristics (e.g., the desired pressure/force sensingrange of the device). The sensors can be flexible.

Although the invention has been described with reference to preferredembodiments, those of skill in the art will recognize that changes canbe made in form and detail without departing from the spirit and scopeof the invention. For example, features of the different embodiments canbe combined with features of other embodiments.

1. A pressure/force sensor including: a diaphragm structure including asensing element; a lead structure extending from the diaphragmstructure, the lead structure including first and second traceselectrically coupled to the sensing element; and wherein the diaphragmstructure and the lead structure include a circuit assembly comprising:a common insulating layer; and a common conductor layer on theinsulating layer, including at least a portion of the sensing elementand at least the first trace.
 2. The sensor of claim 1 wherein: thediaphragm structure includes a base and defines a void region; and theinsulating layer and the conductor layer including the at least theportion of the sensing element are on the base and extend over the voidregion.
 3. The sensor of claim 2 wherein the base includes a metalmember.
 4. The sensor of claim 3 wherein the metal member of the base isa stainless steel member.
 5. The sensor of claim 4 wherein the portionof the sensing element included in the conductor layer includes a firstelectrode.
 6. The sensor of claim 5 wherein: the base includes a movingportion; and the electrode is on the moving portion.
 7. The sensor ofclaim 6 wherein the base further includes spring arms extending from themoving portion.
 8. The sensor of claim 4 wherein: the sensing elementfurther includes a second electrode; and the second electrode is coupledto the second trace.
 9. The sensor of claim 8 and further including avia connecting the second electrode to the second trace.
 10. The sensorof claim 2 wherein: the sensing element includes a strain gauge; and theconductor layer includes the first and second traces.
 11. Apressure/force sensor, comprising: a circuit assembly including adiaphragm portion and a lead portion including: an insulating layer; aconductor layer including a sensor structure at the diaphragm portionand at least one trace at the lead portion that is connected to thesensor structure; and a base, wherein the diaphragm portion of thecircuit assembly is attached to the base.
 12. The sensor of claim 11wherein the base includes a stainless steel member.
 13. The sensor ofclaim 12 wherein: the stainless steel member of the base includes amoving portion; and the diaphragm portion of the circuit assembly isattached to the base.
 14. The sensor of claim 13 wherein the stainlesssteel member of the base includes spring arms extending from the movingmember.
 15. A capacitive pressure sensor, comprising: a first traceassembly, including: a spring metal diaphragm including a base portionand a moving portion; an insulating layer including a diaphragm portionon the moving portion of the diaphragm and a lead portion extending fromthe diaphragm; and a conductor layer on the insulating layer includingan electrode on the diaphragm portion and a trace extending from theelectrode on the lead portion; and a second trace assembly joined to thefirst trace assembly, including: a diaphragm including a base; aninsulating layer having a diaphragm portion on the diaphragm and a leadportion extending from the diaphragm; and a conductor layer on theinsulating layer including an electrode on the diaphragm portion and atrace extending from the electrode on the lead portion.
 16. The pressuresensor of claim 15 wherein the base portion of the first trace assemblyis joined to the base portion of the second trace assembly.
 17. Thepressure sensor of claim 15 and further including a spacer, and whereinthe base portions of the first and second trace assemblies are joined tothe spacer.
 18. The pressure sensor of claim 15 wherein the spring metaldiaphragm includes a plurality of arms coupling the moving portion tothe base portion.
 19. A capacitive pressure sensor, comprising: a traceassembly, including: a spring metal diaphragm including a base portionand a moving portion; an insulating layer having a diaphragm portion onthe moving portion of the diaphragm and a lead portion extending fromthe diaphragm; a conductor layer on the insulating layer including anelectrode on the diaphragm portion and a trace extending from theelectrode on the lead portion; and a metal can electrically andmechanically connected to the base portion of the spring metal diaphragmand defining a void adjacent the moving portion of the spring metaldiaphragm.
 20. A capacitive pressure sensor, comprising: an insulatinglayer including a diaphragm portion, a lead portion, and first andsecond opposite sides; a conductor layer on the first side of theinsulating layer including: an electrode on the diaphragm portion; afirst trace extending from the electrode on the lead portion; and asecond trace on the lead portion; a metal spacer member on the secondside of the insulating layer around the electrode; a conductive viaelectrically connecting the second trace to the metal spacer member; anda metal electrode member mechanically and electrically joined to themetal spacer member.
 21. A strain gauge sensor, comprising: a springmetal base layer having first and second opposite sides and including aspringboard portion and a lead portion; a first insulating layer on thefirst side of the base layer over the springboard portion and the leadportion; a second insulating layer on the second side of the base layerover the springboard portion and the lead portion; a first conductorlayer on the first insulating layer including: a first strain gaugecircuit on the springboard portion; and first traces extending from thefirst strain gauge circuit on the lead portion; and a second conductorlayer on the second insulating layer including: a second strain gaugecircuit on the springboard portion; and second traces extending from thesecond strain gauge circuit on the lead portion.
 22. The strain gaugesensor of claim 21 wherein the first and second strain gauge circuitsare serpentine and mirror images of each other.